The Prohibition of Mixed Marriages Act, Act No 55 of 1949, was an apartheid law in South Africa that prohibited marriages between people of different races. It was among the first pieces of apartheid legislation to be passed following the National Party's rise to power in 1948. Subsequent legislation, especially the Population Registration and Immorality Acts of 1950, facilitated its implementation by requiring all individuals living in South Africa to register as a member of one of four officially defined racial groups and prohibiting extramarital sexual relationships between people of different races.